Robert Downey Junior: Well, I don't know if it's so much the nemesis that I would think about as much as what the character's genesis is and what kind of technology he acquires.

Where do you find him at the beginning, and where does he have to go at the end? Because you still want to save space for the next. But very few fans, me one of them, would disagree that Mandarin was probably Tony Stark's greatest nemesis. Mandarin is badass.

Jon Favreau: "What happens with Rhodey, what happens with War Machine, all that stuff? And then of course the pantheon of villains (Iron Man 2) and the larger Mandarin story.

The problem with the Mandarin is that the way it's depicted in the comic books, you don't want to see that. He has 10 magical rings — that just doesn't feel right for our franchise. So it's either tech-based, or the rings are not really rings.

But maybe with 'Thor' and all those others, you'll introduce magic to that world and it won't seem so out of place." "